1. Field of Invention
The present invention relates to the variable length coding method, more specifically to an efficient coding method that results in shorter code length of representing a data stream.
2. Description of Related Art
Digital audio, image and video have been adopted in an increasing number of applications, which include video telephony, videoconferencing, surveillance system, VCD (Video CD), DVD, and digital TV. In the past almost decades, ISO and ITU have separately or jointly developed and defined some digital video compression standards including MPEG-1, MPEG-2, MPEG-4, MPEG-7, H.261, H.263 and H.264. The success of development of the compression standards fuels wide applications. The advantage of digital image and video compression techniques significantly saves the storage space and transmission time without sacrificing much of the image quality.
One of the main driving sources for the success of the digital audio, image and video compression technology is the data compression algorithms including some alternatives like Huffman coding, arithmetic coding in image and video compression. These coding algorithm reach higher coding efficiency when combining with DCT, Discrete Cosine Transform and quantization which has higher probability of continuous “0s” or/and “no more non-zero” (assigning a code of “EOB, End-Of-Block”). Some other coding algorithms including fixed bit binary coding and variable length coding like Golomb-Rice coding have individual disadvantage and can not reach higher data reduction rate.
This invention of a variable length coding for data compression helps more efficiently reducing the data rate, especially for a group of data.